1. Field of the Invention
The present invention relates generally to fluid discharging apparatus, and, more particularly, to an apparatus and method of cleaning submerged surfaces with cavitating fluids.
2. Description of the Background Art
Various devices exist for dispensing mixtures of liquids and pressurized gas. Such devices are commonly used in pressure washing, the application of liquid fertilizers, snow making, foam making, as well as a variety of other applications. These prior art devices are generally characterized as having inlet ports for receiving the fluids, internal mixing chambers for commingling the fluids, and at least one outlet port for discharging the fluids. In addition, various devices exist for surface cleaning. With regard to this invention, all the abovementioned devices can be easily divided for three groups:                1. Water jet cleaning devices. This group of devices are successfully operated all over the world. (See U.S. Pat. Nos. 5,048,445; 4,716,849; 4,372,242; 5,979,012; 5,893,188; 5,898,970; 5,933,899; 6,003,184; 6,584,992; 5,090,619). In spite of advantages of implementation of those inventions, those devices required serious development and new design.        2. Devices with the implementation of cavitations and/or pulsation water streams, with the common purposes, like drills, scientific and research, feasibility studies, etc (See U.S. Pat. Nos. 4,262,757; 4,389,071; 4,474,251; 4,508,577; 4,681,264; 5,500,134; 6,200,486; 6,221,260). Those inventions are very specific and because of lot disadvantages, have no implementation in practice.        3. Devices with the implementation of cavitations streams for cleaning and other practical purposes. (See RU PATENTS: 2,168,440; 2,168,441; 2,076,824; 2,095,274; RU Published application: 2002,125,729; Certificates for the useful models: 27,559; 27,560; 28,351; 28,669; 29,026; 29,027.) Those devices are in very good efficiency, but they are still have to be serious developed.        
The prior art reveals an apparatus developed for use in cleaning underwater surfaces (RU Patents 2,076,824; 2,095,274). RU Patent No. 2,168,441 (also identified as WO 01/10577 and PCT/RU99/00278) discloses a Hydrodynamic Tool for Surface Cleaning. That device comprises a hand-held device having a pistol grip connected to a source of pressurized water and a barrel section having a nozzle adapted for generating cavitation in flowing fluid discharged therefrom. The device is used to discharge a pressurized stream of water with cavitation generated gas bubbles to assist in removing debris and biological matter that has accumulated on various submerged surfaces.
RU Patent No. 2,168,440 (also identified as WO 01/10576 and PCT/RU/00277) discloses a wheeled configuration for discharging pressurized stream of water with cavitation generated gas bubbles to assist in removing debris and biological matter that has accumulated on various submerged surfaces. The wheeled configuration comprises a generally saucer shaped device wherein a pair of cavitation nozzles are disposed arms pivotally connected to the underside of the device. The wheeled device is maneuvered over a submerged surface by a diver while the spinning cavitation nozzles discharge a pressurized stream of water with cavitation generated gas bubbles to assist in removing debris and biological matter that has accumulated on various submerged surfaces.
The two specifically referenced devices of the prior art, however, are each burdened with similar disadvantages. More particularly, both the hand-held and wheeled devices are limited to discharging cavitating water flow, and are not adapted for the additional discharge of a an abrasive material, such as sand, for more effective removal of debris and marine growth from submerged surfaces. In addition, each of the specifically referenced devices include control levers that have proven difficult to manipulate by an operator in a diving suit.
Accordingly, there exists a need for an improved fluid discharging apparatus wherein cleaning effectiveness is improved by discharging a cavitating stream of pressurized fluid along with a granular abrasive material, such as sand. There further exists a need for such apparatus wherein improved control mechanisms simplify operation.